The method of treatment of open surfaces, liquid and air through the use of UV radiation of continuous spectrum (patent RU 2001629, 1993) is known. In this case sources of impulse UV radiation with impulse duration no more than 5.times.10.sup.-4 sec. are used, they produce radiation intensity no less than 100 Kw/m.sup.2 in treatment area. Bactericidal effect for different microorganisms is achieved in one or several impulses according to integrated energy of radiation dose.
Method of sewage purification from organic substances through use of UV radiation with similar features (patent RU 2001881, 1993 and RU 2031851, 1995) are known. In the latter case UV treatment is combined with use of oxidants.
The devices used in these methods contain an impulse gas discharge lamp, a power supply and control unit with a condenser, a generator of ignitor impulses and an impulse transformer the secondary winding of which is connected in series with the storage condenser and the impulse lamp, thereby providing a discharge circuit (patent RU 2008042, 1994, RU 2031659, 1994 and RU 203 1850, 1994).
The known methods and devices are deficient in efficiency and reliability. The word efficiency as applied to the devices for air disinfection and deodorization designates herein a degree of disinfection or purification of air in a room of predetermined volume which is achieved with a certain consumption of electric energy. In this manner a rise in the efficiency of a unit can be the result of an increase in the bactericidal flow of the UV radiation or of a decrease in the power requirements with all other parameters remaining unchanged.
A severe loss occurs in the transformation of supply line energy into energy of bactericidal UV radiation for the following reasons:
1. During loading of the storage condenser from a direct current source, there occurs a considerable energy loss due to excessively high currents in an early period of the loading process. In addition, elements of the electrical circuit of the unit operated at heavy current lack reliability under intensive operation conditions. PA1 2. For disinfection of air in rooms of a great volume (of the order of 100 m.sup.3 and more) significant power (of the order of 1 kW and more) is delivered to the impulse gas-discharge lamp, which requires effective cooling of the lamp and limitation on the ozone-constituting part of the radiation spectrum. That is to say, the lamp needs to be interposed in a liquid coolant (distilled water) and inductive coupling of the ignitor generator with the discharge circuit is possible only in the form of a transformer because mounting of a special ignitor electrode in a liquid at a high delivered voltage is unavailable. PA1 3. During a change-over from preliminary low-power high-voltage break-down to ground discharge impulse, energy losses occur in association with the fact that in order to produce a high temperature in a radiating plasma the inductance L of the discharge circuit must be lowered (for increasing the maximal current) whereas for reliable generation of the ground discharge impulse the inductance must be increased (for increasing the duration of the ignitor impulse to 1 microsec.) The solution to the problem was one compromise. Because of this, on the one hand the plasma temperature fell below optimum magnitudes, resulting in deficient bactericidal UV radiation and inadequate efficiency of the unit. On the other hand, the discharge becomes unstable in early period thereof, due to inevitable fluctuations and spreads of parameters of the lamp and the plasma. This leads to failure and lack of radiation impulses, that is to say to unreliable and unstable operation of the unit.